Hydraulic cushion for metal presses



May 22, 1928. 1,670,552

- F. J. RODE l HYDRAULIC CUSHION FOR METAL PRESSES 2 Sheets-Sheet 20 J0 20 i7 i g 6 May 22, 1928.

F. J. RODE HYDRAULIC CUSHION FOR METAL PRESSES 2 Sheets-Sheet 2 floushion embodying cylinder and piston Patented May 22, 1928.

FBEDRICH'J. RODE, CHICAGO, ILLINOIS, ASS IGNOR T0 MARQlJllil'PlE TOOL 85 MFG. COMPANY, OF CHICAGO, ILLlNOIS, A CORPORATION OF ILLINOIS.

. HYDRAULIC CUSHION FOR METAL PRESSES.

Application filed April 18, 1927. Serial No. 184,604.

from the other, the work being clamped or 'held by means of a blank or work holding element that co-operates with a reci rocable die member, the blank or work hol ing element being resisted in its movement in one direction'by the said die, and one of the objects of the invention is toprovide an improved hydraulic cushion of this character in which a predetermined quantity of liquid is maintained andused in the cushion, the

members, the liquid being circulated from one side to the other side of the piston, for

establishing the resistance pressure and to the other side of the piston to permit the pressure to be relieved.

A further object is to provide improved means for restoring the blank or work holder to its normal position, and improved means for restraining or holding the blank or work holder at the limit of its downward movement, thereby preventing the same from directly followingthe ram-,on'the upward stroke of the latter. 7 To the attainment of these ends and the accomplishment of other new and useful objects as will appear, the invention consists in the features of novelty in substantially the construction, combination and arrangement of the several parts hereinafter more fully described and, claimed and shown in the accompanying drawings illustrating this invention, and in which Figure 1 is aview in side elevation, partly in section and partly broken away of a single acting press having a cushion constructed in accordance with the principles of this invention applied thereto.

Figure 2is a view similar to- Figure 1, showing thecushion applied to a double acting press. p

Referring more particularly to the drawings, and particularly to the formshowii in Figure 1, the numeral-10 designates generally a supportingstructure of a press having a reciprocable ram 11 to which is fastened .adie 12.

The ram 11 is reciprocated by means of links 13 connected to a crank shaft 14, which latter is rotated in any suitable manner preferably by means of a pulley 15 driven from a source of power (not shown).

Mounted upon the bed plate 16 is a die 17 which co-operates with the die 12 for forming the work 18. A blank or' work holding member 19 encompasses the die 17 and is supported so that in its normal position its upper surface will be substantially flush with the upper surface of the die 17.

The blank or work holder 19 is'supported by means of pins 20 which pass loosely through the bed plate 16 and are supported by means of a pressure pad or plate 21.

All of the above referred to parts are of 'the ordinary and well known construction.

Supported beneath the bed plate 16 and preferably within a pit-22 is a supporting member 23, held in position preferably by means of hangers 24 secured to any suitable stationary part of the, press. 1

Supported by the member 23 is a cylinder 25 which has a piston 26.reciprocable therein. Connected with the piston is a piston rod 27 which passes through a packing box 28. The free end of the piston is secured in any suitable manner such as by means of fastening bolts 29, to the pressure pad or plate 21.

The plate 21 is supported by means of hangers. 30 preferably in the form or rods which are secured to the bed plate 16 and depend therebelow. Encompassing the rods 30 are resiliently yielding elements 31, preferably in the form of coil springs, one end 0 which engage and rest against the lower face of the pad 21, and'the other ends engage and rest against washers 32 on the respective hangers, and which washers are held in position by means of suitable nuts 33. The. springs 30 are of The cylinder 25 is rovided with an opening 34, preferably ad acent the bottom thereof, and connecting with the opening 34 is a such a size that energy stored therein Wlll serve as a means valve casing'35 in which is arranged a valve 36, which closes communication between the opening 34 and the casing 35. A spring 37 adapted to be regulated by means of an adjusting device 38 controls the action of the valve 36 and against the stress of which spring 37 the valve 36 is adapted to be unseated by the pressure created upon the liquid 39 in the cylinder beneath the piston 26.

The pressure upon the valve 36 by the spring 37 may be predetermined according to the degree of pressure which it is adapted to establish upon the liquid 39before the valve 36 will be unseated.

When the valve 36 is'open communication will be established between the cylinder through the passa e 34 and casing with the conduit 40 w ich has communication with the cylinder 25, preferably adjacent the top thereof as at 41 and on the other side of the piston 26, so that the liquid, when the valve 36 is open, will flow from beneath the piston around to the top side of the piston.

The supply of liquid for the cylinder may be provided through a pipe 42 leading from a suitable source (not shown) andin"which pipe 42 a check valve 43 is arranged to prevent the liquid from being forced back into the pipe 42. v

When the desired supply of liquid is placed in the cylinder 29, and assuming the parts to be in the position shown in Figure 1, when the ram descends the blank holding member '19 will be lowered through the medium of the pins 20, the pressure pad or plate 21 will be lowered, thereby forcing the piston 26 downwardly in the cylinder 25 against the liquid 39 therein. This pres sure upon the liquid will continue and the valve 36 will remain closed until the pressure upon the liquid exceeds the pressure of the spring 37 upon the valve 36. When the pressure upon the valve 36 is thus exceeded the valve will be unseated and the liquid will flow through the conduit 40 to the other side of the piston.

As the pressure pad or plate 21 descends energy will be stored in the springs 31, but this energy, as before stated, will be negligible in so far as creating any resistance action to the plate 2], is concerned. The springs 31 are provided solely for thepurpose of restoring the pad to its normal osition. When the pad 21 reaches the limit'of its downward movement and upon the ascent of the ram 11, the pressure pad or plate 21 will be restored by the energy in the spring, and the piston 26 will be raised in the cylinder 25, forcing the liquid there above through another conduit 44,- which has communication with the cylinder on both sides of the piston.

As a means for holding the pad 21 in its lowermost position to prevent the same from returning directly with the ram, means are provided for controlling the passage 44 to prevent the liquid from passing from the top to the bottom of the piston, thereby preventing the resiliently yielding elements 31 from'returning the pad 21. To that end there is provide-din the conduit 44 a valve 45 for closing the' conduit 44, and which valve is adapt-ed to be operated at a predetermined time in the cycle of operation of .the press so as to open the valve.

This may be accomplished by means of av rod 46 which is connected preferably by means of a link 47 with a lever 48. The

.lever 48 is fulcrumed intermediate its ends as at 49 to a support 50. The other end of the lever is connected as at 51 with-a stem of the valve 45 so that when the lever 48 is rocked the valve will be correspondingly opened or closed. r

Any suitable means may be provided for actuating the rod 46 but preferably the other end of the rod is connected asat 52.to the crank shaft 14.

In Figure 2 of the drawings the cushion pass loosely through the bed or bolster plate l6 and contact with and rest uponthe pressure pad or plate 21.

The operation of this form of the cushion is the same as in Figure With this invention 1t will be manifest that the hydraulic pressure may be controlled at any time during the cycle of operation of the press by the adjustment of the tension of the resiliently yielding element or spring 37 by adjusting theha'ndle 38 and by such an adjustment the degree of pressure necessary to unseat the valve 36 may be controlled at will.

It will also be manifest that through-the medium of the valvev45 the return of the pressure pad or plate 21 under the influence of the resiliently yielding elements or springs 31 may be delayed to a predetermined time in the cycle of operation of the press, according to the time of operation at which the valve 45 is set to be actuated through the medium of the operative connection with a movable part of thepress.

While the preferred forms of the invention have been herein shown and described, it is to'be understood that-various changes may be made in the details of construction and in the combination and arrangement of the several parts, within the scope of the claims, without departing from the spirit of this invention.

What is claimed as new is 1. A pressure cushion for sheet metal presses embodying a pressure pad, a cushion for resisting the movement of the pad in one direction, said cushion embodying cylinder and piston members one of which is operativoly connected with the pad, a liquid in the cylinder, a conduit leading the liquid from one side to the other side of the piston, valve mechanism for controlling said conduit and adapted to be set at a predetermined resistance pressure and operable against said pressure under a predetermined pressure created upon the liquid by the movement of the pad in one direction, means for returning the pad, and means for de laying the return of the pad by the last said means, the last said means embodying a second conduit for leading the liquid from one side to the other side of the piston, and means for controlling the last said conduit.

2. A pressure cushion for sheet metal presses embodying a pressure pad, a cushion for resisting the movement of the pad in 1 one direction, said cushion embodying cylinder and piston members one of which is operatively connected with the pad, a liquid in the Cylinder, a conduit leading the liquid from one side to the other side of the piston,

valve mechanism for controlling said conduit and adapted to be set at a predetermined resistance pressure and operable against said pressure under a predetermined pressure created upon the liquid by the movement oi the pad in one direction, means for returning the pad, means for relaying the return of the pad by the last said means, the last said means embodying 'a second conduit for leading the liquid from one side to the other side of the piston, and a valve operating automatically at a predetermined time in the cycle of operation of the press for controlling the last saidconduit.

3. A pressure cushion for sheet metal presses embodying a pressure pad, means for restoring the pad, a cushion for resisting movement of the pad in one direction, said cushion embodying cylinder andpiston members one of which is connected with said pad, a predetermined supply of liquid in the cylinder, two conduits each serving to lead the liquid in the cylinder fromone side of the piston to theother side thereof,'a valve for controlling one of the passages, means whereby said valve may be set to be opened only at a predetermined pressure created upon the liquid by the movement of the pad in one direction,a valve for controlling the other of said conduits, whereby the return of the said pad will be delayed, and

means for operating the valve at a predetermined time in the cycle of operation of the press, the first recited means constituting the sole means for-returning said pad. 4. A pressure cushion for sheet metal presses embodying a pressure pad, means for restoring the pad, a cushion for resisting movement of the pad in one direction, said cushion embodying cylinder and piston members one of which is connected with said pad, a predetermined supply of liquid in the cylinder, two conduits each serving to lead the liquid in the cylinder from one side of the piston to the other side thereof, a

valve for controlling one of the passages, means whereby sald, valve may be set to be opened only at a predetermined pressure created upon the liquid by the movement against the resistance pressure of the liquid being negligible as a resistance pressure to the movement of the pad.

5. A pressure cushion for sheet metal presses embodying cylinder and piston members, hydraulic'means for resisting the relative movement of said members in one direction, a' conduit ,for leading the liquid from'one side to the other side of the piston,

a valve for closing said conduit against movement of the liquid in one direction therethrough, variable yielding means for holding said valve closed, an adidtional conduit for leading the liquid from one side to the other side of the piston, a valve for closing said additional conduit against the passage of liquid therethrough, and means connected with an operating part of the press for intermittently opening and closing the last recited valve.

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6. A pressure cushion for sheet metal presses embodying cylinder and piston members, hydraulic means for resisting the relative movement of said members in one direction, a conduit for leading the liquid from one side to the othersideof the piston, a

valve for closing said conduit against movement of the liquid in one direction there: through, variable'yielding means forholding said valve closed, an additional conduitfor leading the liquid from one side to the other side of the piston, a valve vfor closing.

said additional conduit against the passage of liquid therethrough, means connected with an operating part of the press for intermittently opening and closing the last rendered active by the relative movement of recited valve, and resiliently yielding means i the cylinder and piston in one direction for causing a relative movement thereof in the opposite direction.

7. A pressure cushion for sheet metal presses embodying a pressure pad, an hydraulic cushion for resisting'the movement of the pad in one direction, means other than the cushion for supporting and for from one side to the other side of the piston,

avalve for controlling the last said conduit,

and means automatically operating the last,

' pad restoring means embodying a resiliently I said valve at a predetermined time inthe cycle of operation of the press.

I 8. A pressure. cushion for sheet metalpresses embodyinga pressure pad, an by draulic cushion for reslstmg the movement of the pad in one direction, means other than the cushion for supporting and for restoring the pad, said cushion embodying .cylinder and piston members one of which is operatively connected with the pad, a liquid in the cylinder, a conduit for leading the liquid from. one side to the other of the piston, a valve for closing the conduit, said.

valve being'operable to open the conduit under a predetermined pressure created upon the liquid by the movement of the pad,

an additional conduit for leading the liquid from one side to the other side of the piston, a valve for controlling the last said conduit, and means automatically operating the last said valve at a predetermined time in the cycle of operation of the press, the said yielding element in which energy will be stored by the movement of the pad against the resistance pressure of said cushion, the energy of the said pad restoring means being negligible as a resistance pressure to the' action of the pad.

. 9. A pressure cushion for sheet metal -'presses embodying a pressurepad, hanger members connected with a fixed part of the press, resiliently yielding members supported by the hanger members and operating upon the pad to support and restore the same, an hydraulic cushion for resisting the movement of the pad in one 'direc-- tion, said cushion embodyingcvlinder and piston members relatively mova 1e and one.

of which is connected with the pad,.two

separate conduits for transferring the liq-- uid from one side of the piston to the other side thereof, valves individual to the-conduits for closing them, means creating 11 predetermined resistance pressure upon one of said valves, and means responsive in its operation to the operation of the press for opening and closing the other of said valves.

10. A pressure cushion for sheet metal presses embodying a pressure pad, hanger members connected with a fixed part of the press, resiliently yielding members supported by the hanger members and operating upon the pad to support and restore the same, an hydraulic cushion for resisting the movement of the pad in one direction, said cushion embodying cylinder and piston members relatively movable and one of which is connected with-the pad, two separate conduits for transferring the liquid from one side of the piston to the other side thereof,- valves individual to the conduits for closing them, means creating a predetermined resistance' pressure upon oneof said valves, and means responsive in its operation to the operation of the-press for opening and closing the other of said valves, the operation of the said resiliently yielding means being negligible as a resistance pressure tothe action of the said pad against the resistance pressure of the said cushion.

11; The combination with a movable support for a blank or work holder, resiliently yielding means for supporting and for restoring said support, a piston connected with the first said support, hydraulic means for resisting the movement of the support and piston in one direction, variable resistance means for controlling the resistance pressure exerted by the piston upon the liquid, a conduit for conductin the liquid from the pressure side of the piston to the other side thereof, and a valve for controlling said conduit whereby the return'of the first said support and the piston may be delayed.

12. The combination with a movable support for a blank or work holder, resiliently storing said support, a piston connected with the first said support, hydraulic means for resisting the movement of the support and piston in one direction, variable resistance means for controlling the resistance pressure-exerted by the piston upon the liquid, a conduit for conducting the liquid from the pressure sideof the piston to the other side thereof, a valve for controlling said conduit, and means responsive to the movement of a part of the press at a predetermined time in the cycle of operation of the press for controlling the said valve whereby the return of the said draw ring may be delayed.

In testimony whereof I have signed my name to this'specification, on this 29th day of March, A. D. 1927.

' g REnnIoH J. RODE. 

